SAA induces Ca²⁺ mobilization and ERK1/2 phosphorylation in FPRL1/LXA4R-transfected cells.

(A) Stable transfectants, or the untransfected RBL-2H3 cells, were loaded with Indo-1/am and stimulated with SAA (2 μM) or MMK-1 (100 nM). Elevation of intracellular Ca²⁺ was observed in FPRL1/LXA4R-transfected but not the untransfected RBL or FPR-transfected RBL cells. (B) SAA and MMK-1 stimulate activation of ERK1/2 in FPRL1/LXA4R-transfected cells but not in the untransfected cells, as measured by Western blotting using an antiphospho-ERK1/2 antibody (upper blot). Equal loading of samples was determined by an antibody against unphosphorylated ERK1/2 (lower blot).